Engineers have created a smartphone HIV test that costs $35 to make

Let’s be honest: Smartphones aren’t necessarily thought of as devices that help to slow the spread of sexually transmitted diseases. In fact, research has found that transmission rates go up when hookup sites – even ones on the tamer end, like CraigsList – come to town.

The dongle, as the team writes in the journal Science Translational Medicine, costs just $34 to make (an amount that could drop further if mass produced). It uses the phone’s power and data collection, and incorporates simple optics and fluid control to process a finger prick of blood.

While paper-based options for home testing do exist, and work much in the way that…